Structure and passivation effects of mono- and dihydrogen complexes in GaAsyN1-y alloys -: art. no. 216401

In GaAsyN1-y, the presence of a few percent of N induces a large reduction of the GaAs band gap that vanishes upon hydrogenation. In the present Letter, the energetics of N-H complexes and their effects on the band structure of the GaAs0.97N0.03 alloy have been investigated by first-principles density functional methods. We find that monohydrogen N-H+ and dihydrogen N-H-2* complexes are formed depending on doping. Moreover, only N-H-2* complexes account for the neutralization of nitrogen effects. A model is proposed that clarifies the passivation mechanism of nitrogen by H.